"The Israeli air force blew up a convoy which had just crossed the border from Syria into Lebanon," an unnamed security source told Agence France-Press.

A "well-placed defense analyst" told John Ray of ITV News that the strike was in Hezbollah Lebanese territory and the missile struck a "truck of scud and antiaircraft missiles" headed to members of the Iran-backed militant group. WSJ reported that "it wasn't immediately clear on which side of the border it occurred."

Two officials told The Associated Press Israel had been planning to hit a shipment of weapons for the last few days because it contained Russian-made SA-17 anti-aircraft missiles, which would be strategically "game-changing" in the hands of Hezbollah.

On Monday Israel Army Radio reported that security chief Yaakov Amidror was headed to Russia to discuss the Syrian crisis. On Tuesday Al-Monitor reported that IDF intelligence chief Maj. Gen. Aviv Kochavi was traveling to Washington for consultations with American officials.

Israel has indicated that any sign that Syrian President Bashar al-Assad was losing control of his chemical and/or conventional weapons could trigger Israeli military strikes.

On Tuesday Israeli Air Force (IAF) chief Major-General Amir Eshel told an international aerospace conference that the IAF was involved in "a campaign between wars," working with Israeli intelligence agencies in often covert missions "to reduce the immediate threats [and] to create better conditions in which we will be able to win the wars, when they happen."

An Israeli Defense Force spokeswoman declined to comment on the reports.

Vice Premier Silvan Shalom, when asked on Israel Radio if there was unusual activity on the northern front, said: "The entire world has said more than once that it takes developments in Syria very seriously, developments which can be in negative directions ... Of course any development which is a development in a negative direction would be something that needs stopping and prevention."

In October Sudan accused Israel of bombing a arms factory that was widely believed to be owned by Iran and used to supply weapons to Hamas in Gaza.